Vulnerability · Published Oct 31, 2026 · Assigned by Wordfence
CVE-2026-101326Ninja Forms <= 3.15.5 - Authenticated (Subscriber+) Arbitrary Shortcode Execution via '{wp:user_display_name}' Merge Tag via display_name
Medium 5.4
In plain English
A medium-severity code injection in Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder from kstover. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).
Official description
The The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 3.15.5 This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for authenticated attackers, with subscriber-level access and above, to execute arbitrary shortcodes. Exploitation requires that an administrator has configured at least one Ninja Forms field with its Default Value set to the {wp:user_display_name} merge tag on a publicly accessible page; a Subscriber need only set their display_name to a shortcode string via their profile and then visit that page.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| kstover | Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder | 0 – through 3.15.5 |
Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/05dccb32-e638-4929-a788-3998bc3acd75?source=cve
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/MergeTags/WP.php#L189
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Display/Render.php#L278
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Display/Render.php#L268
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Config/MergeTagsWP.php#L128
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Abstracts/MergeTags.php#L94
- https://wordpress.org/plugins/ninja-forms/
- https://plugins.trac.wordpress.org/changeset/3749135/ninja-forms/trunk/includes/Display/Render.php